Cylinder head of an internal combustion engine comprising two intake and two exhaustvalves for each cylinder



July 18, 1967 O SKATSCHE 3,331,359

CYLINDER HEAD OF AN INTERNAL COMBUSTION ENGINE COMPRISING TWO INTAKE ANDTWO EXHAUST VALVES FOR EACH CYLINDER Filed July 21, 1965 3 Sheets-Sheetl I. Aw;

3,331,359 PRISING 5 Sheets-Sheet 2 STION ENGINE COM FIG. 4

' IIII O. SKATSCHE III/I TWO INTAKE AND TWO EXHAUST VALVES FOR EACHCYLINDER (Ill CYLINDER HEAD OF AN INTERNAL COMBU July 18. 1967 FiledJuly 21, 1965 y 18, 1967 I o. SKATSCHE 3,331,359

CYLINDER HEAD OF AN INTERNAL COMBUSTION ENGINE COMPRISING TWO INTAKE ANDTWO EXHAUST VALVES FOR EACH CYLINDER Filed July 21, 1965 5 Sheets-Sheet3 United States Patent 3,331,359 CYLINDER HEAD OF AN INTERNAL COMBUS-TION ENGINE COMPRISING TWO INTAKE AND TWO EXHAUST VALVES FOR EACHCYLINDER Otllmar Skatsche, Graz, Austria, assignor to Hans List, Graz,Austria Filed July 21, 1965, Ser. No. 473,614 Claims priority,application Austria, Aug. 21, 1964, A 7,274/64 4 Claims. (Cl. 123-75)ABSTRACT OF THE DISCLOSURE A cylinder head of an internal combustionengine of which each cylinder comprises two intake valves and twoexhaust valves with a reversal of the valves with every second cylinderof the engine. Four spiral ducts of the inlet ports of two adjacentcylinders each terminating in a common suction port and are arranged ina central relation to the four intake valves associated therewith.

For heavy-duty internal combustion engines generally equipped withintake valves for each cylinder assembly, vigorous and regularturbulence of the air entering the combustion chamber is of the essence.However, it is generally very difficult to suitably arrange and designtwist-producing inlet ports of multiple-valve cylinder heads so as toobtain the best flow conditions possible. The reasons why previouselforts of engine builders invariably ended in some sort of compromisesolution are mainly of a structural nature.

Quite a number of combinations of oblique and oblique-and-spiral ductsare already known. However, experience has shown oblique ducts topresent inferior flow properties and lower twist rates than spiralducts. Moreover, oblique ducts are much more sensitive to lack ofcasting precision with regard to the achievement of a uniform twist inall cylinders of a multi-cylinder engine than are spiral ducts. Thissensitivity naturally affects four-valve cylinder heads, each comprisingtwo oblique ducts at the inlet end to an even greater extent.

Similar conditions prevail also in the conventional combination of onespiral duct and one oblique duct in fourvalve cylinder heads. In orderto achieve the best flow properties possible in this instance, both theintake valves and the valve seat rings of the oblique duct and of thespiral duct are inevitably of different design so as to obtainapproximately identical flow conditions in both valves.

Consequently, the use of two spiral ducts in four-valve cylinder headsis desirable. Since in automotive, and in particular, in truck enginesfeaturing two intake valves for each cylinder these are usually arrangedby pairs in transverse relation to the crankshaft axis as thisarrangement represents the simplest and cheapest solution with regard tothe operation of the valves, it was the obvious thing to do to arrangetwo twist ducts extending in transverse relation to the crankshaft axisone behind the other. However, the draw-back of this arrangement residesin the fact that due to the inherent properties of spiral ducts thesecond spiral duct located behind the first as viewed in the directionof flow, is handicapped with regard to its flow characteristics,particularly as far as the attainable twist rate is concerned, bygreater resistance to flow in the longer feed duct as compared with thefirst spiral duct located in front as viewed in the direction of flow.

For that reason, large-sized engine types were built wherein the intakevalves are arranged in a row in parallel relation to the crankshaft axisand equipped with individual identical spiral ducts extending intransverse relation to the crankshaft axis. However, this arrangementrequires a comparatively expensive and complicated valve gear for theoperation of the intake and exhaust valves which is both uneconomic andhardly practicable for engine construction in view of certain design andspace requirements.

It is the object of the invention to overcome the drawbacks of cylinderheads of conventional design for internal combustion engines comprisingtwo intake and two exhaust valves for each cylinder and to improve flowconditions at the suction end. According to the invention this isachieved by the provision of spiral ducts of at least approximatelyequal shape and length extending in pairs as far as the top of thecylinder head where they terminate in a common suction port. This designmakes for identical flow conditions in both spiral ducts as a result ofwhich identical twist rates obtain both for the intake valves of acylinder assembly and for all cylinders. Flow conditions are furtherimproved by the downdraft effect produced by the vertical arrangement ofthe suction ports. Another advantage of the design of the cylinder headaccording to the invention resides in the possibility of preserving thearrangement of the intake valves in a row extending in parallel relationto the crankshaft as is customary particularly with truck engines,thereby keeping the cost involved and space required for the operationof the valves on a moderately low level.

According to a preferred embodiment of the invention, the two spiralducts meet inside the cylinder head and terminate in a common suctionport preferably located in the plane of symmetry including thecrankshaft axis between the intake valves, thereby shortening the flowroutes leading to the intake valves and reducing the resistance to flowaccordingly.

Finally, according to the invention the location of the intake andexhaust valves can be reversed in every second cylinder, the four spiralducts of each pair of adjacent cylinders terminating in a common suctionduct preferably half-way between the respective intake valves. Thecombination of four spiral ducts each to form a structural unit exposedto the impact of the air not only simplifies the general design of thecylinder head but assures also absolutely identical flow conditions inthe four spiral ducts.

Further details of the invention will appear from the followingdescription of two embodiments of the invention with reference to theaccompanying drawings in which:

FIG. 1 shows a horizontal cross-sectional view of a cylinder head of aninternal combustion engine comprising two intake and two exhaust valvesfor each cylinder on line I-I of FIG. 2 representing a verticalcross-sectional view on line 11-11 of FIG. 1, Whereas FIGS. 3 and 4 showsimilar views of another variant of the cylinder head on lines IIIIH andlV-IV respectively,

FIG. 5 showing a vertical cross-section in transverse relation to thecrankshaft axis on line VV of FIG. 3.

The illustration shown in FIG. 5 is also applicable to the variant shownin FIG. 1. The drawings show only a portion of the internal combustionengine extending apapproximately over two adjacent cylinder assemblies.

In both types of cylinder heads the cylinder fairing 2 is located atopthe cylinder head 1, with a packing 4 in between, the said fairing beingclosed on top by a cover 3 with the insertion of a packing 5. Theinjection nozzle 6 of each cylinder assembly arranged in coaxialrelation to the cylinder axis together with the nozzle-holder 7 enclosedin a nozzle-holder protection tube 8, is inserted in a through bore ofthe cylinder head 1.

Each cylinder assembly comprises two intake valves 9 and 9' and twoexhaust valves 10 and 10, both the intake valves 9, 9 and the exhaustvalves 10, 10' being arranged by pairs in planes extending inperpendicular relation to the crankshaft axis. The valve gear is locatedabove the cylinder head 1 inside the cylinder head fairing 2 andcomprises a vertically movable bridge 11 transmitting the motion of therocker arm 12 actuated by the push rod 13 to the valve couple 9, 9 and10, 10, respectively.

The inlet ports 14, 14' of the valves 9, 9 are designed as spiral ductsfor the purpose of imparting an initial twist to the ingoing air forcombustion and are of approximately equal shape and length so that thetwist rates for the two intake valves 9, 9 are also identical. The inletports 14, 14' extend in an upward direction towards the top of thecylinder head 1. In the embodiment illustrated in FIGS. 1 and 2 theinlet ports 14 and 14 of each cylinder assembly meet inside the cylinderhead 1 so as to form a common duct 15 terminating in a vertical suctionport 16 defined by a tube 17 inserted in the area of the upper sealingflange of the cylinder head 1. The suction ports 16 of all cylinderassemblies are located in the plane of symmetry between the intakevalves 9 and 9' including also the crankshaft axis of the engine.

Referring to the cylinder head shown in FIGS. 3 to 5, the location ofthe intake and exhaust valves 9, 9' and 10, 10' respectively, ofadjacent cylinder assemblies is inverted so that the intake valves 9, 9of each pair of adjacent cylinders can be combined so as to form asingle unit for the supply of air for combustion. The inlet ports 14,14' of each of these valve groups extend jointly in an upward directiontoward the top of the cylinder head so as to form a common duct 15 alsoterminating in a vertical suction port 16 in the area of the uppersealing surface of the cylinder head 1. In this instance, the suctionport 16 is arranged in a central relation to the associated four intakevalves.

The cylinder heads hereabove described with references to theaccompanying drawings are but a few examples taken from a multitude ofpossible embodiments of the invention. In particular, the scope of thepresent invention is by no means restricted with regard to thecross-sectional design of the inlet ports.

What is claimed is:

1. A cylinder head of an internal combustion engine of which eachcylinder comprises two intake valves and two exhaust valves, the saidvalves extending in perpendicular relation to a crankshaft axis of theinternal combustion engine, each of the said intake valves comprising aninlet port designed as a spiral duct, the spiral ducts of all inletports being of approximately the same shape and length, pairs of thesaid spiral ducts ascending to the top of the cylinder head andterminating there in a common suction duct, the location of the intakevalves and exhaust valves being reversed with every second cylinder ofthe internal combustion engine, and the four spiral ducts of twoadjacent cylinders each terminating in the said common suction port.

2.. A cylinder head as claimed in claim 1, wherein the said four spiralducts of two adjacent cylinders each are located in a central relationto the four intake valves associated therewith.

3. A cylinder head of an internal combustion engine comprising aplurality of cylinders, each cylinder comprising two intake valves andtwo exhaust valves, the said valves extending in perpendicular relationto a crankshaft of the internal combustion engine, the location of theintake valves and exhaust valves being reversed with every secondcylinder of the internal combustion engine, each intake valve comprisingan inlet port designed as a spiral duct, and a suction port in the topof the cylinder head, the four spiral ducts of two adjacent cylinderseach ascending to the top of the cylinder head and terminating in thesaid suction port.

4. A cylinder head as claimed in claim 3, wherein the said four spiralducts of two adjacent cylinders each are located in a central relationto the four intake valves associated therewith.

References Cited UNITED STATES PATENTS 2,318,914 5/1943 Anderson et al123-30 2,909,971 8/1959 Kauifmann et al. 123--30 X 3,020,896 2/1962Meurer et al. 123-30 3,054,390 9/1962 Meurer et al. 123-30 3,125,0753/1964 Wittek 123-30 3,240,190 3/1966 Christian et al. 12330 FOREIGNPATENTS 1,201,809 7/1959 France.

844,352 8/ 1960 Great Britain.

899,760 6/ 1962 Great Britain.

MARK NEWMAN, Primary Examiner.

WENDELL E. BURNS, Assistant Examiner.

3. A CYLINDER HEAD OF AN INTERNAL COMBUSTION ENGINE COMPRISING APLURALITY OF CYLINDERS, EACH CYLINDER COMPRISING TWO INTAKE VALVES ANDTWO EXHAUST VALVES, THE SAID VALVES EXTENDING IN PERPENDICULAR RELATIONTO A CRANKSHAFT OF THE INTERNAL COMBUSTION ENGINE, THE LOCATION OF THEINTAKE VALVES AND EXHAUST VALVES BEING REVERSED WITH EVERY SECONDCYLINDER OF THE INTERNAL COMBUSTION ENGINE, EACH INTAKE VALVE COMPRISINGAN INLET PORT DESIGNED AS A SPIRAL DUCT, AND A SUCTION PORT IN THE TOPOF THE CYLINDER HEAD, THE FOUR SPIRAL DUCTS OF TWO ADJACENT CYLINDERSEACH ASCENDING TO THE TOP OF THE CYLINDER HEAD AND TERMINATING IN THESAID SUCTION PORT.